Question

How do you say 3 - (-4) as an equivalent sum

Answer 1

When you have minus negative it is the same result as plus positive, so 3+4 is what you're looking for

Answer 2

$\bf 3-(-4)~~ \begin{cases} -(-4)=-1(-4)\\ \qquad\qquad -1\cdot -4\\ \qquad\qquad +4 \end{cases}~\hspace{8em} 3+4$